T1083_file-and-directory-discovery

T1083 File and Directory Discovery

High-Level Description

Adversaries may enumerate files and directories or may search in specific locations of a host or network share for certain information within a file system. Adversaries may use the information from File and Directory Discovery during automated discovery to shape follow-on behaviors, including whether or not the adversary fully infects the target and/or attempts specific actions.

Many command shell utilities can be used to obtain this information. Examples include dir, tree, ls, find, and locate. Custom tools may also be used to gather file and directory information and interact with the Native API. Adversaries may also leverage a Network Device CLI on network devices to gather file and directory information (e.g. dir, show flash, and/or nvram).

Some files and directories may require elevated or specific user permissions to access.

Kill Chain Phase

• Discovery (TA0007)

Platforms: ESXi, Linux, macOS, Network Devices, Windows

What to Check

• Identify if File and Directory Discovery technique is applicable to target environment
• Check ESXi systems for indicators of File and Directory Discovery
• Check Linux systems for indicators of File and Directory Discovery
• Check macOS systems for indicators of File and Directory Discovery
• Assess detection coverage (1 detection strategies)

How to Test

Atomic Red Team Tests

The following tests are from Atomic Red Team and provide actionable ways to test this technique:

Atomic Test 1: File and Directory Discovery (cmd.exe)

Find or discover files on the file system. Upon successful execution, this test will output the results of all the data discovery commands to a specified file.

Supported Platforms: windows

dir /s c:\ >> #{output_file}
dir /s "c:\Documents and Settings" >> #{output_file}
dir /s "c:\Program Files\" >> #{output_file}
dir "%systemdrive%\Users\*.*" >> #{output_file}
dir "%userprofile%\AppData\Roaming\Microsoft\Windows\Recent\*.*" >> #{output_file}
dir "%userprofile%\Desktop\*.*" >> #{output_file}
tree /F >> #{output_file}

Atomic Test 2: File and Directory Discovery (PowerShell)

Find or discover files on the file system. Upon execution, file and folder information will be displayed.

Supported Platforms: windows

ls -recurse
get-childitem -recurse
gci -recurse

Atomic Test 3: Nix File and Directory Discovery

Find or discover files on the file system

References:

http://osxdaily.com/2013/01/29/list-all-files-subdirectory-contents-recursively/

https://perishablepress.com/list-files-folders-recursively-terminal/

Supported Platforms: linux, macos

ls -a >> #{output_file}
if [ -d /Library/Preferences/ ]; then ls -la /Library/Preferences/ > #{output_file}; fi;
file */* *>> #{output_file}
cat #{output_file} 2>/dev/null
find . -type f
ls -R | grep ":$" | sed -e 's/:$//' -e 's/[^-][^\/]*\//--/g' -e 's/^/ /' -e 's/-/|/'
locate *
which sh

Atomic Test 4: Nix File and Directory Discovery 2

Find or discover files on the file system

Supported Platforms: linux, macos

cd $HOME && find . -print | sed -e 's;[^/]*/;|__;g;s;__|; |;g' > #{output_file}
if [ -f /etc/mtab ]; then cat /etc/mtab >> #{output_file}; fi;
find . -type f -iname *.pdf >> #{output_file}
cat #{output_file}
find . -type f -name ".*"

Atomic Test 5: Simulating MAZE Directory Enumeration

This test emulates MAZE ransomware's ability to enumerate directories using Powershell. Upon successful execution, this test will output the directory enumeration results to a specified file, as well as display them in the active window. See https://www.mandiant.com/resources/tactics-techniques-procedures-associated-with-maze-ransomware-incidents

Supported Platforms: windows

$folderarray = @("Desktop", "Downloads", "Documents", "AppData/Local", "AppData/Roaming")
Get-ChildItem -Path $env:homedrive -ErrorAction SilentlyContinue | Out-File -append #{File_to_output}
Get-ChildItem -Path $env:programfiles -erroraction silentlycontinue | Out-File -append #{File_to_output}
Get-ChildItem -Path "${env:ProgramFiles(x86)}" -erroraction silentlycontinue | Out-File -append #{File_to_output}
$UsersFolder = "$env:homedrive\Users\"
foreach ($directory in Get-ChildItem -Path $UsersFolder -ErrorAction SilentlyContinue)
{
foreach ($secondarydirectory in $folderarray)
 {Get-ChildItem -Path "$UsersFolder/$directory/$secondarydirectory" -ErrorAction SilentlyContinue | Out-File -append #{File_to_output}}
}
cat #{File_to_output}

Manual Testing

If Atomic Red Team tests are not applicable, manually verify the technique by:

1. Identify Attack Surface: Determine if the target environment is susceptible to File and Directory Discovery by examining the target platforms (ESXi, Linux, macOS).

2. Assess Existing Defenses: Review whether mitigations for T1083 are in place. If defenses are absent or misconfigured, this technique may be exploitable.

3. Execute Test: Use tools and methods described in the MITRE ATT&CK page and external references below.

Remediation Guide

No specific mitigations documented for this technique.

Detection

Recursive Enumeration of Files and Directories Across Privilege Contexts

Risk Assessment

CWE Categories

References

• Windows Commands JPCERT
• US-CERT-TA18-106A
• Atomic Red Team - T1083
• MITRE ATT&CK - T1083